7 times 55 is 385, but what is the answer if both 7 and 55 are negative numbers? Here we will determine if the answer to negative 7 times negative 55 is positive 385 or negative 385.
There are many different ways to explain and determine if the answer to negative 7 times negative 55 is -385 or +385 using mathematical terms such as additive inverse and mathematical laws like the Distribute Law.
We will take a different approach - process of elimination: We will simply test if -385 is the correct answer using basic algebra.
We will test if -385 is correct by setting up the equation negative 7 times negative 55 equals negative 385, and then simplifying the equation to see if it is true.
(-7) (-55) = (-385)
Divide both sides of the equation by (-55) :
|
| = |
|
The numerator and denominator on the left side both have (-55) which even each other out and can be removed:
| (-7) = |
|
The numerator and denominator on the right side both have a minus sign (-) which even each other out and can be removed:
| (-7) = |
|
A numerator of 385 and denominator of 55 on the right side is the same as 385 divided by 55 which is 7. Now we end up with this untrue equation:
(-7) = (7)
-7 is NOT equal to 7, thus we have proven that negative 7 times negative 55 is not equal to -385. The answer must therefore be 385:
-7 x -55 = 385
The above applies to all math problems where you multiply two negative numbers. Multiplying two negative numbers such as negative 7 times negative 55 will always have a positive answer.
Negative Times Negative Calculator
Here you can multiply another two negative numbers together.
What is negative 7 times negative 56?
Here is the next problem on our list that we have explained and calculated.
Copyright | Privacy Policy | Disclaimer | Contact